There is no dawn on the moon, no dusk, no atmosphere to catch and spread the light of the sun. When the lunar night ends—a night two earth weeks long—the sun simply pops over the horizon, bringing its intolerable heat. But the sky remains black—black and sprinkled with stars agleam with a light unknown on earth. At night the temperature is 250 degrees below zero; by day it is the heat of boiling water. Yet the sun is but an intense circle of white aloft in a nigrescent sky.

Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.(See the entry for nigrescent in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.)